JP6454796B2 - Nonwoven abrasive article and method for producing the same - Google Patents

Description

Detailed Description of the Invention

(Technical field)
The present disclosure relates generally to nonwoven abrasive articles and methods of making and using them.

(background)
Nonwoven abrasive articles generally have a nonwoven web (eg, bulky and coarse fiber nonwoven web), abrasive particles, and a binder (usually referred to as a “binder”), which binder agent is a nonwoven web. The inner fibers are bonded together and the abrasive particles are fixed to the nonwoven web. Examples of non-woven abrasive articles include non-woven abrasive hand pads and surface-finished abrasive discs and belts such as those sold under the trade name “SCOTCH-BRITE” by 3M Company (St. Paul, Minn.). Can be mentioned.

  Another type of nonwoven abrasive article is a nonwoven abrasive wheel. Examples of nonwoven abrasive wheels include spiral abrasive wheels (nonwoven abrasive webs spirally wound around a core) and integral abrasive wheels (stacked of one or more individual nonwoven abrasive web disks) Is). Nonwoven polishing wheels are also available from 3M Company (St. Paul, Minnesota) under the trade name “SCOTCH-BRITE”.

  In one manufacturing method, a nonwoven fibrous web is coated with a binder precursor material. The abrasive particles are then applied to the binder precursor material and then it is cured to secure the abrasive particles to the fibrous web.

  Historically, bulky and coarse nonwoven abrasive articles have been manufactured using a variety of coating techniques. For example, in US Pat. No. 2,958,593 (Hoover et al.), A nonwoven abrasive article is made by spray application of a relatively thin slurry containing a solution consisting of a binder, a solvent, and abrasive particles. Alternatively, the abrasive particles may be applied by a drop coating method as described in International Patent Application Publication No. 2014/137972 (A1) (Kaur et al.).

  U.S. Pat. No. 6,017,831 (Beardsley et al.) Deposits countless uniformly dispersed fine abrasive particles on a fiber coated with a binder precursor (preferably by sedimentation by gravity). Yet another coating technique is described. The use of electrostatic coatings to direct abrasive particles and adhere them to bulky nonwoven materials is described in US Pat. No. 7,393,371 (O'Gary et al.).

(Overview)
Despite the above disclosure, the inventors have unexpectedly found that, under suitable conditions, these abrasive particles are one in a state where the abrasive particles extend perpendicularly in all directions around the fiber axis. It has been found that abrasive platelets can be continuously coated along the fibers of the nonwoven fibrous web so that they are arranged as layers (preferably densely).

In a first aspect, the present disclosure provides:
A non-woven abrasive article,
A bulky and coarse nonwoven fibrous web containing entangled fibers;
An abrasive platelet fixed to the fibers entangled with at least one binder material,
The majority of abrasive platelets each provide a nonwoven abrasive article that is bonded in the edge direction to at least one of the entangled fibers.

  Nonwoven abrasive articles according to the present disclosure can be in the form of hand pads, floor pads, surface finish pads, flap brushes, discs, belts, etc., or can be converted into an integral or spiral polishing wheel.

In a second aspect, the present disclosure provides a method of manufacturing an abrasive article, the method comprising:
i) providing a bulky and coarse nonwoven fibrous web comprising a plurality of entangled fibers;
ii) coating at least a portion of a bulky, coarse open nonwoven fibrous web with a first curable binder precursor to provide a coated fibrous web;
iii) electrostatically depositing a plurality of abrasive platelets on at least a portion of the first curable binder precursor;
iv) at least partially curing the first curable binder precursor;
The majority of the abrasive platelets are each bonded in the edge direction to at least one of the entangled fibers.

  In certain preferred embodiments, the method comprises coating at least a portion of the first curable binder precursor and the abrasive platelet with the second curable binder precursor, and at least the second binder precursor. And partially curing.

  Unexpectedly and advantageously, the nonwoven abrasive articles according to the present disclosure exhibit superior polishing performance over conventional nonwoven abrasive articles specific to the abrasive arts.

As used herein,
The term “adhered in the edge direction” with respect to the abrasive platelets adhered to the fibers means that the abrasive platelets are adhered to the fibers mainly at their periphery.

  The term “closely-packed” with respect to abrasive platelets bonded to fibers means that the majority of abrasive platelets (eg, at least 50%, at least 60%, or at least 75%) It means that it is arranged away from adjacent abrasive platelets by a distance smaller than the width of those adjacent abrasive platelets.

  The term “orthogonal” means forming an angle of 75 degrees to 105 degrees (preferably 80 degrees to 100 degrees, more preferably 85 degrees to 95 degrees).

  The term “abrasive platelet” resembles a flake characterized by a fine flat body and / or a thickness substantially shorter than the width and length (randomly crushed, intentionally shaped and / or Refers to shaped (eg, thin truncated triangular pyramid) or any abrasive particles. Abrasive platelets generally have two opposing major surfaces that define the length and width of the abrasive platelets, and these major surfaces are at least 1 with a thickness disposed therebetween. Joined along a perimeter that includes two lines and / or at least one surface. For example, the thickness is 1/2, 1/3, 1/4, 1/5, 1/6, 1/7, 1/8, 1/9, or 1/10 or less of the length and / or width. It may be.

  The term “length” refers to the longest dimension of the object.

  The term “width” refers to the longest dimension of an object perpendicular to the length.

  The term “thickness” refers to the remaining dimensions that are perpendicular to the length and width.

  The features and advantages of the present disclosure will be further understood in view of the “DETAILED DESCRIPTION” and the appended claims.

1 is a perspective view of an exemplary nonwoven abrasive article 100. FIG. 1B is an enlarged view of a region 1B of the nonwoven fabric abrasive article 100 shown in FIG. 1A. FIG. 1 is a perspective view of an exemplary spiral polishing wheel 200. FIG. 1 is a perspective view of an exemplary integrated polishing wheel 300. FIG. It is a microscope picture of each nonwoven fabric abrasive article produced in the following "Examples" section. It is a microscope picture of each nonwoven fabric abrasive article produced in the following "Examples" section. It is a microscope picture of each nonwoven fabric abrasive article produced in the following "Examples" section. It is a microscope picture of each nonwoven fabric abrasive article produced in the following "Examples" section. It is a microscope picture of each nonwoven fabric abrasive article produced in the following "Examples" section. It is a microscope picture of each nonwoven fabric abrasive article produced in the following "Examples" section. It is a microscope picture of each nonwoven fabric abrasive article produced in the following "Examples" section. It is a microscope picture of each nonwoven fabric abrasive article produced in the following "Examples" section. It is a microscope picture of each nonwoven fabric abrasive article produced in the following "Examples" section. It is a microscope picture of each nonwoven fabric abrasive article produced in the following "Examples" section. It is a microscope picture of each nonwoven fabric abrasive article produced in the following "Examples" section. It is a microscope picture of each nonwoven fabric abrasive article produced in the following "Examples" section.

  Reference signs used repeatedly in the specification and figures are intended to represent the same or similar features or elements of the present disclosure. It should be understood that many other modifications and embodiments within the scope and spirit of the present disclosure may be devised by those skilled in the art. The drawings may not be drawn to scale.

(Detailed explanation)
Nonwoven polishing wheels such as monolithic polishing wheels and spiral polishing wheels are bulky fibrous bonded nonwoven sheets containing superabrasive grains such as diamond or cubic boron nitrate abrasive particles or Can be made from the web. Such sheets or webs can be made by a process that typically involves coating a slurry curable binder precursor on or over the nonwoven fibrous web. In forming a monolithic or spiral abrasive wheel, the nonwoven fibrous web is typically compressed (ie, densified) compared to the nonwoven fibrous web used for bulky and coarse nonwoven articles. .

  Nonwoven fiber webs suitable for use are known in the abrasive art. Typically, a nonwoven fibrous web comprises a web of entangled fibers. The fibers may include continuous fibers, short fibers, or combinations thereof. For example, the fibrous web may comprise short fibers having a length of at least about 20 millimeters (mm), at least about 30 mm, or at least about 40 mm, and less than about 110 mm, less than about 85 mm, or less than about 65 mm, but more Short fibers and longer fibers (eg, continuous fibers) may also be useful. The fiber has a fineness or linear density of at least about 1.7 decitex (dtex, ie grams / 10000 meters), at least about 6 dtex, or at least about 17 dtex, and less than about 560 dtex, less than about 280 dtex, or less than about 120 dtex. However, fibers having smaller and / or higher linear densities may also be useful. Mixtures of fibers having different linear densities may also be useful, for example, to provide an abrasive article that provides a particularly favorable surface finish when in use. When using a spunbond nonwoven, the filaments may have a substantially larger diameter, for example, 2 mm or less in diameter or greater.

  Fibrous webs can be made, for example, by conventional airlaid, carded, stitchbonded, spunbonded, wet laid and / or meltblown procedures. The airlaid fiber web can be made, for example, using equipment such as that commercially available from Rando Machine Company (Macedon, NY) under the trade name “RANDO WEBBER”.

  The nonwoven fibrous web is typically selected to be compatible with the adhesive binder and abrasive particles, as well as with other components of the article, and is typically a curable binder precursor. It can withstand processing conditions (eg temperature) as used during body application and curing. The fibers can be selected to affect the properties of the abrasive article, such as, for example, flexibility, elasticity, durability or service life, abrasion, and finish properties. Examples of fibers that may be suitable include natural fibers, synthetic fibers, and mixtures of natural and / or synthetic fibers. Examples of synthetic fibers include polyester (eg, polyethylene terephthalate), nylon (eg, hexamethylene adipamide, polycaprolactam), polypropylene, acrylonitrile (ie, acrylic), rayon, cellulose acetate, polyvinylidene chloride-vinyl chloride copolymer And those made from vinyl chloride-acrylonitrile copolymers. Examples of suitable natural fibers include cotton, wool, jute, and linen. The fibers may be virgin material or, for example, recovered material or waste material regenerated from cutting, carpet manufacturing, fiber manufacturing, or fiber processing. The fibers can be homogeneous or can be composites such as bicomponent fibers (eg, co-spun core-sheath fibers). The fibers may be stretched and crimped, but may also be continuous filaments such as those formed by an extrusion process. A combination of fibers may be used.

  Prior to coating and / or impregnation with the binder precursor composition, the nonwoven fibrous web typically has a weight per unit area (ie basis weight) of at least about 50 grams / square meter (gsm), At least about 100 gsm, or at least about 150 gsm, and / or less than about 600 gsm, less than about 500 gsm, as measured before any coating (eg, using a curable binder precursor or an optional prebond resin) Or having less than about 400 gsm, but larger and smaller basis weights may be used. Further, prior to impregnation with the curable binder precursor, the fibrous web is typically at least about 3 mm, at least about 6 mm, or at least about 10 mm, and / or less than about 100 mm, less than about 50 mm, or less than about 25 mm. However, thicker and thinner ones may also be useful.

  Often it is beneficial to apply the prebond resin to the nonwoven fibrous web prior to coating with a curable binder precursor, as is known in the abrasive art. The prebond resin, for example, helps to maintain the integrity of the nonwoven fibrous web during operation and can also promote adhesion of the urethane binder to the nonwoven fibrous web. Examples of the prebond resin include phenol resin, urethane resin, glue, acrylic resin, urea formaldehyde resin, melamine formaldehyde resin, epoxy resin, and combinations thereof. The amount of the prebond resin used in this method is typically adjusted to a minimum amount suitable for bonding fibers at a cross-linking contact. If the nonwoven fibrous web includes heat-bondable fibers, thermal bonding of the nonwoven fibrous web may also be beneficial in maintaining the integrity of the web during processing.

  Nonwoven abrasive articles comprising bulky and coarse nonwoven fibrous webs (eg, handpads, surface finish discs and belts, flap brushes, or nonwoven abrasive webs used to make integral or spiral abrasive wheels) Then, the numerous gaps between adjacent fibers that are not substantially filled with binder and abrasive particles result in a very low density composite structure that is reticulated over a number of relatively large communicating voids. Have The resulting lightweight, bulky and extremely open fiber structure is essentially non-occlusive and non-filling, especially when used with liquids such as water and oil. These structures can also be easily washed with a simple wash with a washing solution, dried, allowed to stand for a considerable period of time and then reused. To this end, the voids in these nonwoven abrasive articles can constitute at least about 75%, preferably more than the total space occupied by the composite structure.

  Suitable curable binder precursors (eg, suitable for the first and / or second curable binder precursors) include resole phenolic resins, novolac phenolic resins, epoxy resins, polymerizable acrylic monomer oligomers and polymers, Examples include alkyd resins, cyanate resins, aminoplast resins, urea formaldehyde resins, urethane resins (one-pack type and two-pack type), and combinations thereof. Depending on the curable binder precursor system selected, a suitable curing agent (eg, crosslinker, catalyst, or initiator) may be present. The selection and amount of such suitable hardeners are well known in the abrasive art.

  The curable binder composition can include various additives. For example, conventional resin fillers (eg, calcium carbonate or fine fibers), lubricants (eg, alkali metal salts of stearic acid and light petroleum), crushing aids (eg, potassium borofluoride), wetting agents or surfactants ( For example, sodium lauryl sulfate), antifoams, pigments, dyes, biocides, coupling agents (eg, organosilanes), plasticizers (eg, polyalkylene polyols or phthalates), thickeners, and their Combinations are listed. Typically, the curable binder precursor includes at least one solvent (eg, isopropyl alcohol, methyl ethyl ketone, water) to facilitate coating the curable binder precursor on the nonwoven fibrous web, This is not a requirement.

  In some embodiments, the curable binder precursor is a urethane prepolymer. Examples of useful urethane prepolymers include polyisocyanates and their block forms. Typically, blocked polyisocyanates are substantially mixed with isocyanate-reactive compounds (eg, amines, alcohols, thiols) under ambient conditions (eg, at temperatures in the range of about 20 ° C. to about 25 ° C.). However, when sufficient heat energy is applied, the blocking agent is released, thereby reacting with the amine curing agent to produce an isocyanate functional group that forms a covalent bond.

  Useful polyisocyanates include, for example, aliphatic polyisocyanates (for example, hexamethylene diisocyanate or trimethylhexamethylene diisocyanate), alicyclic polyisocyanates (for example, hydrogenated xylylene diisocyanate or isophorone diisocyanate), aromatic polyisocyanates. (Eg, tolylene diisocyanate or 4,4′-diphenylmethane diisocyanate), adducts of any of the aforementioned polyisocyanates with polyhydric alcohols (eg, diols, low molecular weight hydroxyl group-containing polyester resins, and / or water) , Adducts of the aforementioned polyisocyanates (for example, isocyanurates, biurets), and mixtures thereof.

  Useful commercially available polyisocyanates include, for example, polyisocyanates commercially available from Chemtura (Middlebury, Conn.) Under the trade name “ADIPRENE” (for example, ADIPRENE L 0311, ADIPRENE L 100, ADIPRENE L 167, ADIPREN L 213, ADIPREN L 315, ADIPREN L 680, ADIPREN LF 1800A, ADIPREN LF 600D, ADIPRENE LFP 1950A, ADIPREN LFP 2950A, ADIPREN LFP 2950A, ADIPREN LFP 5950A, ADIPREN LFP 2950A, ADIPREN LFP 2950A Commercially available under the trade name "MONDUR" Polyisocyanates (eg, MONDUR 1437, MONDUR MP-095, or MONDUR 448) and Air Products and Chemicals (Allentown, Pa.) Under the trade names “AIRTHANE” and “VERSATHANE” Commercially available polyisocyanates (for example, AIRTHANE APC-504, AIRTHANE PST-95A, AIRTHANE PST-85A, AIRTHANE PET-91A, AIRTHANE PET-75D, VERSATHANE STE-95A, VERSATHANE STE-P95, VERSATAN VERSATHANE SME-90A, and VERSATHANE MS-90A).

  To extend the pot life, for example, polyisocyanates as described above can be blocked with blocking agents according to various techniques known in the art. Exemplary blocking agents include ketoximes (eg, 2-butanone oxime), lactams (eg, ε-caprolactam), malonic acid esters (eg, dimethyl malonate and diethyl malonate), pyrazoles (eg, 3,5-dimethylpyrazole), tertiary alcohols (eg, t-butanol or 2,2-dimethylpentanol), phenols (eg, alkylated phenols), and mixtures of the above alcohols. Examples include alcohols.

  Exemplary useful commercially available block polyisocyanates include the trade names “ADIPREN BL 11”, “ADIPREN BL 16”, “ADIPREN BL 31”, “ADIPREN BL 46”, and “ADIPREN BL 500” from Chemtura. Products sold under the trade name "TRIXENE" (for example, TRIXENE BL 7641, TRIXENE BL 7642, TRIXENE BL 7772, and TRIXENE BL 7774) by Baxenden Chemicals (Accraton, England) Is mentioned.

  Typically, the amount of any urethane prepolymer present in the curable binder precursor is 10-40% by weight, more typically 15-30% by weight, based on the total weight of the curable binder precursor. Even more typically 20 to 25% by weight, but amounts outside these ranges may be used.

  Exemplary curing agents for urethane prepolymers include aromatic, alkyl-aromatic, or alkyl polyfunctional amines, preferably primary amines. Examples of useful amine curing agents include 4,4′-methylenedianiline, the trade name “CURITHANE 103” commercially available from Dow Chemical Company, and the trade name commercially available from Bayer (Pittsburgh, Pa.). Polymeric methylene dianiline, 1,5-diamine-2-methylpentane, tris (2-aminoethyl) amine having a functionality of 2.1 to 4.0, including what is known as “MDA-85” 3-aminomethyl-3,5,5-trimethylcyclohexylamine (ie isophoronediamine), trimethylene glycol di-p-aminobenzoate, bis (o-aminophenylthio) ethane, 4,4′-methylenebis (dimethyl) Anthranilate), bis (4-amino-3-ethylphenyl) methane (e.g. Nippon Kayaku Company, Ltd. (sold under the trade name “KAYAHARD AA” by Tokyo, Japan) and bis (4-amino-3,5-diethylphenyl) methane (eg, Lonza) , Ltd.) (sold under the trade name “LONZACURE M-DEA” by Basel, Switzerland). If desired, the polyol (s) can be added to the curable binder precursor and the cure rate can be altered (eg, delayed) depending on the needs of the intended application, for example. The amine curing agent should be present in an amount (ie, an effective amount) effective to cure the blocked polyisocyanate to the extent required for the intended application; for example, the amine curing agent is an isocyanate (or blocked isocyanate). ) May be present in the range of 0.8 to 1.35, such as 0.85 to 1.20, or 0.90 to 0.95. Stoichiometric ratios outside the range can also be used.

  One method of manufacturing a nonwoven abrasive article according to the present invention includes applying a prebond coating (eg, by roll coating or spray coating) to a nonwoven fibrous web, curing the prebond coating, Impregnating a fibrous web with a make layer precursor having a first curable binder precursor (e.g., commonly referred to as "make coat", by roll coating or spray coating), and the curable binder precursor Applying abrasive particles, and optionally a second curable binder precursor (which may be the same or different) to cover the make layer precursor and the abrasive particles (generally “size coat” or “size layer”). The step of applying a precursor) and then this curing And curing the binder precursor, comprising in this order.

  The amount of curable binder precursor in the make layer precursor (and optional size layer precursor) should generally be sufficient for the abrasive platelets to adhere firmly to the nonwoven fibrous web in the finished product. However, an appreciable amount of abrasive platelets (eg, less than 10%, less than 5%, less than 2%) are deposited on other abrasive platelets to form a double layer. There are not many. In some embodiments, preferably a curable binder precursor in an amount of 25 to 1000 grams per square meter (gsm), more preferably 100 to 1000 gsm, and even more preferably 75 to 750 gsm on a nonwoven fibrous web. (Except for any solvent that may be present) is coated, but values outside these ranges can also be used.

  Useful abrasive platelets may be the result of a crushing operation (eg, crushed abrasive particles classified for shape and size) or a molding operation (ie, a shaped abrasive platelet), The polishing precursor material is shaped (eg, shaped), dried, and converted to a ceramic material. Abrasive platelets obtained by crushing can also be used in combination with abrasive platelets resulting from the molding operation. The abrasive platelets may be, for example, in the form of individual particles, agglomerates, composite particles, and mixtures thereof.

  The abrasive platelets must have sufficient hardness and surface roughness to function as crushed abrasive particles during the polishing process. Preferably, the abrasive platelet has a Mohs hardness of at least 4, at least 5, at least 6, at least 7, or even at least 8.

  The crushed abrasive platelets can be obtained from commercial sources by known methods and / or by sizing the crushed abrasive particles, such as by using a shape sorting table known in the art.

  Suitable abrasive particles (including abrasive platelets and optionally block or needle-like abrasive particles) that may be included in a nonwoven abrasive article according to the present disclosure include crushed abrasive particles, Ceramic aluminum oxide materials such as molten aluminum oxide, heat treated aluminum oxide, white molten aluminum oxide, commercially available as 3M CERAMIC ABRASIVE GRAIN from 3M Company (St. Paul, Minn.), Brown aluminum oxide, blue aluminum oxide, Silicon carbide (including green silicon carbide), titanium diboride, boron carbide, tungsten carbide, garnet, titanium carbide, diamond, cubic boron nitride, garnet, fused alumina zirconia, iron oxide, chromia, zirconia, titania, tin oxide ,quartz Including feldspar, flint, emery, sol-gel derived ceramic (eg α-alumina), and combinations thereof. Examples of sol-gel derived abrasive particles from which abrasive platelets can be isolated and methods for their preparation are described in U.S. Pat. Nos. 4,314,827 (Leithiser et al.), 4,623,364 (Cottringer). et al.), 4,744,802 (Schwabel), 4,770,671 (Monroe et al.), and 4,881,951 (Hoopman et al.). Can do. The abrasive particles may also comprise abrasive agglomerates such as those described, for example, in US Pat. No. 4,652,275 (Bloecher et al.) Or 4,799,939 (Bloecher et al.). Conceivable. In some embodiments, the abrasive particles are coupled with a coupling agent (eg, an organosilane coupling agent) or other physical treatment (eg, iron oxide or titanium oxide) to enhance adhesion of the crushed abrasive particles to the binder. It may be surface-treated. The abrasive particles may be treated before they are combined with the binder, or may be surface treated in situ by including a coupling agent in the binder.

  Preferably, the abrasive particles (and particularly the abrasive platelets) comprise ceramic abrasive particles such as, for example, sol-gel derived polycrystalline alpha alumina particles. Ceramic abrasive particles composed of α-alumina, magnesium alumina spinel, and rare earth hexagonal aluminate crystallites are disclosed in, for example, US Pat. No. 5,213,591 (Celikkaya et al.), US Patent Application Publication No. Can be made using sol-gel precursor alpha alumina particles according to the methods described in 2009/0165394 (A1) (Culler et al.) And 2009/0169816 (A1) (Erickson et al.). it can.

  Further details regarding methods for producing sol-gel derived abrasive particles are described, for example, in U.S. Pat. Nos. 4,314,827 (Leithiser), 5,152,917 (Pieper et al.), 5,435,816. No. (Spurgeon et al.), No. 5,672,097 (Hoopman et al.), No. 5,946,991 (Hoopman et al.), No. 5,975,987 (Hoopman et al.). ), 6,129,540 (Hoopman et al.), And US Patent Application Publication No. 2009/0165394 (A1) (Culler et al.).

  The majority of abrasive particles are abrasive platelets. The abrasive platelet is preferably at least 50 weight percent, preferably at least 55 weight percent, at least 60 weight percent, at least 65 weight percent, at least 70 weight percent, at least at least 50 weight percent of the total weight of abrasive particles contained in the nonwoven abrasive article. It constitutes 75 weight percent, at least 80 weight percent, at least 85 weight percent, at least 90 weight percent, at least 95 weight percent, at least 99 weight percent, or even 100 weight percent, although this is not a requirement.

  In some preferred embodiments, useful abrasive particles (especially in the case of abrasive platelets) may be shaped abrasive particles, US Pat. Nos. 5,201,916 (Berg), 5,366, 523 (Rowenhorst (Re 35,570)) and 5,984,988 (Berg). U.S. Patent No. 8,034,137 (Erickson et al.) Describes alumina abrasive particles that are formed into a specific shape and then crushed to form debris that retains some of the original shape features. . In some embodiments, the shaped alpha alumina particles are precision molded (i.e., the shape is determined at least in part by the shape of the plurality of cavities in the production tool used to produce them). Have). Details regarding such abrasive particles and methods for making them can be found, for example, in US Pat. Nos. 8,142,531 (Adefris et al.), 8,142,891 (Culler et al.), And 8,142,532 (Erickson et al.), And US Patent Application Publication Nos. 2012/0227333 (Adefris et al.), 2013/0040537 (Schwabel et al.), And 2013. / 0125477 (Adefris).

  A surface coating on the abrasive particles may be used to improve the adhesion between the crushed abrasive particles of the abrasive article and the binder, or may aid in the electrostatic deposition of the abrasive particles. In one embodiment, a surface coating such as that described in US Pat. No. 5,352,254 (Celikkaya) is used in an amount of 0.1-2% surface coating based on the weight of the abrasive particles. Also good. Such surface coatings are described in U.S. Patent Nos. 5,213,591 (Celikkaya et al.), 5,011,508 (Wald et al.), 1,910,444 (Nicholson), 3,041,156 (Rowse et al.), 5,009,675 (Kunz et al.), 5,085,671 (Martin et al.), 4,997. 461 (Markhoff-Matheny et al.) And 5,042,991 (Kunz et al.). Furthermore, the surface coating can prevent capping of the shaped abrasive particles. Capping is a term that describes a phenomenon in which metal particles from a workpiece being polished become welded to the top of the abrasive article. Surface coatings that perform the above functions are known to those skilled in the art.

  The abrasive platelets have a length in the range of 0.1 micrometers to 3.5 millimeters (mm), more typically 0.05 mm to 3.0 mm, and more typically 0.1 mm to 2.6 mm. Although selected to have thickness and / or width, other lengths and widths may also be used.

  The abrasive platelet is selected to have a thickness in the range of 0.1 micrometer to 1.6 mm, more typically 1 micrometer to 1.2 mm, although other thicknesses are also used. Also good. In some embodiments, the plate-like crushed abrasive particles can have an aspect ratio (length to thickness) of at least 2, 3, 4, 5, 6, or more.

  In some preferred embodiments, the abrasive platelet is a shaped abrasive platelet and is defined by a top surface and a bottom surface and a plurality of sidewalls disposed therebetween. Examples include a platelet shaped as a truncated triangular prism or a truncated triangular pyramid.

  The length, width and thickness of the abrasive platelets can be determined individually or based on an average, as desired. Appropriate techniques include inspection and measurement of individual particles, and automatic image analysis techniques according to the test method ISO 13322-2: 2006 “Particle Size Analysis—Image Analysis Method—Part 2: Dynamic Image Analysis Method”. The inspection and measurement used (for example, using a dynamic image analyzer such as the CAMSIZER XT image analyzer manufactured by Lecce Technology, Hahn, Germany).

  Preferably, the abrasive platelets have nominally the same size and shape, but this is not a requirement.

  Suitable abrasive particles (including abrasive platelets and other shapes) can be independently sized according to defined nominal grades recognized in the abrasive industry. Exemplary classification standards recognized in the abrasive industry include the American National Standards Institute (ANSI), the Federation of European Producers of Abrasives (FEPA), and JIS. (Japanese Industrial Standards) are listed. For example, ANSI4, ANSI6, ANSI8, ANSI16, ANSI24, ANSI36, ANSI46, ANSI54, ANSI60, ANSI70, ANSI80, ANSI90, ANSI100, ANSI100, ANSI120, ANSI150, ANSI180, ANSI220, ANSI240. , ANSI280, ANSI320, ANSI360, ANSI400, and ANSI600. FEPA grades include F4, F5, F6, F7, F8, F10, F12, F14, F16, F16, F20, F22, F24, F30, F36, F40, F46, F54, F60, F70, F80, F90, F100, F120, F150, F180, F220, F230, F240, F280, F320, F360, F400, F500, F600, F800, F1000, F1200, F1500, and F2000. As JIS grade notation, JIS8, JIS12, JIS16, JIS24, JIS36, JIS46, JIS54, JIS60, JIS80, JIS100, JIS150, JIS180, JIS220, JIS240, JIS280, JIS320, JIS360, JIS400, JIS600, JIS800, JIS1000, JIS1500 JIS 2500, JIS 4000, JIS 6000, JIS 8000, and JIS 10,000 are mentioned.

  Alternatively, crushed abrasive particles are rated to a nominal screening grade using a US standard test sieve in accordance with ASTM E-11 “Standard Specification for Wire Cloth and Sieves for Testing Purposes”. Can be attached. ASTM E-11 establishes requirements for the design and construction of test sieves using media consisting of woven wire cloth mounted on a frame to classify materials according to specified particle sizes. A typical notation may be expressed as -18 + 20, where the crushed abrasive particles pass through a test sieve that meets ASTM E-11 No. 18 sieve specifications, and ASTM E It means that it remains in the test sieve that satisfies the No. 11 No. 20 sieve specification. In one embodiment, the crushed abrasive particles have the majority of particles pass through a No. 18 mesh test sieve and remain on the No. 20, 25, 30, 35, 40, 45, or 50 mesh test sieve. It has a particle size that can be In various embodiments, the crushed abrasive particles are -18 + 20, -20 / + 25, -25 + 30, -30 + 35, -35 + 40, 5-40 + 45, -45 + 50, -50 + 60, -60 + 70, -70 / + 80, -80 + 100,- It can have a nominal screening grade of 100 + 120, −120 + 140, −140 + 170, −170 + 200, −200 + 230, −230 + 270, −270 + 325, −325 + 400, −400 + 450, −450 + 500, or −500 + 635. Alternatively, a specialized mesh size such as -90 + 100 can be used.

Typically, the coating weight of the abrasive particles (regardless of the other components in the curable binder precursor) depends on, for example, the particular binder used, the process of applying the abrasive particles, and the size of the abrasive particles Can do. For example, the coating weight of abrasive particles on the nonwoven web (before any compression) is at least 100 grams / square meter (gsm), at least 600 gsm, or at least 800 gsm, and / or less than 3000 gsm, less than about 2000 gsm, or less than about 1000 gsm Although heavier or lighter coating weights may also be used.
Electrostatic coating is used to apply the abrasive platelets to the make-coated nonwoven fibrous web. During electrostatic coating, an electrostatic charge is applied to the abrasive particles, which creates a potential difference between the particles and the electrically grounded nonwoven web. The potential difference attracts abrasive particles to the nonwoven web. Electrostatic coatings tend to direct abrasive particles and tend to provide better polishing performance.

  One useful electrostatic coating apparatus has a conveyor belt that moves through an electrostatic field. The coater applies a make layer precursor coating on the nonwoven fibrous web, after which the web path guides the nonwoven through an electrostatic field on the conveyor belt. An abrasive feeder applies abrasive particles to form a layer of abrasive particles on the conveyor belt. As the conveyor belt moves the particle layer through the electrostatic field, abrasive particles are transferred upward from the conveyor belt to the make layer precursor coated nonwoven fibrous web. Further details regarding this type of particle coating process as applied to the manufacture of coated abrasive articles are described in US Pat. No. 8,869,740 (B2), except that the nonwoven fibrous web should be replaced with a backing. ) (Moren et al.).

  The resulting structure is exposed to a state sufficient to solidify the make layer precursor. Details regarding the voltage and deposition rate of a particular binder precursor coated nonwoven fibrous web can be readily determined by one skilled in the art. An electrostatic coating may be applied to one or both sides of the binder precursor coated nonwoven fibrous web. Other electrostatic coating methods can also be used, such as firing the particles toward the nonwoven web using conventional spraying methods and then directing the particles on the fibers by an applied electrostatic charge.

  At this point, the size layer precursor may optionally be applied over at least a portion of the make layer precursor and abrasive particle (eg, abrasive platelet) platelets. The size layer precursor includes a second curable binder precursor that may be the same as or different from the make layer precursor. For example, any material used for the make layer precursor may be used for the size layer precursor. Similarly, the make layer precursor process conditions may be used to coat and cure the size layer precursor to form a size layer and abrasive particles disposed on at least a portion of the make layer. The resulting structure is exposed to a state sufficient to solidify the size layer precursor.

  As a result of the electrostatic coating process, typically in combination with controlling the amount of binder precursor to avoid overloading, the abrasive platelets are for each at least one fiber to which they are bonded. The abrasive platelets can be oriented to be orthogonal. In addition, the abrasive platelets can be arranged in at least some embodiments to be substantially orthogonal to at least one fiber to which they are bonded (i.e., 70-110 degrees with that fiber). Preferably, an angle of 80 to 100 degrees is formed).

  The inventors have found that conventional electrospray processes are generally inefficient to implement the present disclosure.

  An exemplary embodiment of a nonwoven abrasive article 100 is shown in FIGS. 1A and 1B. The bulky and coarse low density fiber web 110 is formed from filaments 115 held together by a binder 120. The abrasive platelet 140 is secured to the fibrous web 110 on the exposed surface of the filament 115 by a binder 120. The majority of abrasive platelets 140 are oriented perpendicular to at least one fiber to which it is bonded, and the sword 150 will be directed outward with respect to the fiber.

  For example, a spiral-type abrasive wheel may be prepared by applying a non-woven fibrous web to a core member so that the impregnated non-woven fibrous layer is compressed after the size layer precursor is applied to the make layer and abrasive particles and partially cured. For example, it can be produced by wrapping around a tubular or rod-like core member) and then fully curing the size layer precursor. A spiral abrasive wheel 200 is shown in FIG. 2, in which the nonwoven fibrous web 210 is coated with a binder that removes abrasive particles (eg, as in FIGS. 1A and 1B) from the layered nonwoven fibers. Secure to the web and bond the layers of layered nonwoven fibrous web 210 together. The non-woven fibrous web 210 is disposed around the core member 230 in a spiral shape and is attached to the core member 230. If desired, the spiral grinding wheel may be revised prior to use to remove surface irregularities, for example using methods known in the abrasive art.

  Similarly, a one-piece abrasive wheel is manufactured similar to a spiral abrasive wheel, for example, except that the size layer precursor coated web is stacked and compressed prior to curing instead of wrapping the size layer precursor coated web. be able to. An integral nonwoven polishing wheel 300 having a plurality of compressed and cured nonwoven polishing layers 310 is shown in FIG. After curing the curable binder precursor, the resulting molten slab can be punched to form a polishing wheel having a center hole 320.

  In the manufacture of abrasive wheels, when compressing a layer of impregnated nonwoven fibrous web, typically one or more layers are compressed to a layer density of 1 to 1 in their uncompressed state. A slab having a density 10 times is formed. Next, typically depending on the curable binder precursor selected and the size of the slab / van, it is typically thermoformed (eg, 2-20 hours) into a slab at an elevated temperature (eg, 135 ° C.). Apply.

  In addition to the abrasive wheels described above, the method of manufacturing a nonwoven abrasive article according to the present disclosure is useful, for example, for making hand pads, floor pads, flap brushes, surface finish pads, disks, and belts.

  Further details regarding non-woven abrasive articles, abrasive wheels, and methods of making them can be found, for example, in US Pat. Nos. 2,958,593 (Hoover et al.) And 5,591,239 (Larson et al.). No. 6,017,831 (Beardsley et al.) And US Patent Application Publication No. 2006/0041065 (A1) (Barber, Jr.).

Selected embodiments of the present disclosure In a first embodiment, the present disclosure comprises:
A bulky and coarse nonwoven fibrous web containing entangled fibers;
An abrasive platelet fixed to the fibers entangled with at least one binder material,
The majority of the abrasive platelets each provide a nonwoven abrasive article that is bonded in the edge direction to at least one of the entangled fibers.

  In a second embodiment, the present disclosure provides a nonwoven abrasive article according to the first embodiment, wherein the abrasive platelet is a triangular abrasive platelet.

  In a third embodiment, the present disclosure provides a nonwoven abrasive article according to the first or second embodiment, wherein the abrasive platelets are densely packed along the length of the interlaced fibers.

  In a fourth embodiment, the present disclosure provides any one of the first to third embodiments, wherein the nonwoven abrasive article is a hand pad; a floor pad; a flap brush; or a surface finish pad, disk, or belt. A non-woven abrasive article is provided.

  In a fifth embodiment, the present disclosure provides a nonwoven abrasive article according to any one of the first to fourth embodiments, wherein the abrasive platelets have nominally the same size and shape.

  In a sixth embodiment, the present disclosure provides any of the first to fifth embodiments, wherein the majority of the abrasive platelets are arranged to be orthogonal to the entangled fibers to which the abrasive platelets are bonded. A non-woven abrasive article is provided.

  In a seventh embodiment, the present disclosure provides a first to a second abrasive platelet, wherein the abrasive platelet is defined by an upper surface and a lower surface and a plurality of sidewalls disposed therebetween. 6. A nonwoven abrasive article according to any one of the six embodiments is provided.

  In an eighth embodiment, the present disclosure provides a spiral nonwoven fabric polishing wheel comprising a nonwoven fabric abrasive article according to any one of the first to seventh embodiments spirally wound and compressed.

In a ninth embodiment, the present disclosure is a method of manufacturing an abrasive article,
i) providing a bulky and coarse nonwoven fibrous web comprising a plurality of entangled fibers;
ii) coating at least a portion of a bulky, open, nonwoven fibrous web with a first curable binder precursor to provide a coated fibrous web;
iii) electrostatically depositing a plurality of abrasive platelets on at least a portion of the first curable binder precursor;
iv) at least partially curing the first curable binder precursor;
The majority of the abrasive platelets are each bonded in the edge direction to at least one of the entangled fibers.

  In a tenth embodiment, the present disclosure includes coating at least a portion of a first curable binder precursor and an abrasive platelet with a second curable binder precursor; and a second curable binder precursor. The method according to the ninth embodiment further comprises the step of at least partially curing.

  In an eleventh embodiment, the present disclosure provides a nonwoven abrasive article comprising: at least one hand pad; at least one floor pad; at least one flap brush; or at least one surface finish pad, disk, or belt. The method according to the ninth or tenth embodiment is further provided, further comprising the step of converting into at least one.

In the twelfth embodiment, the present disclosure provides:
v) The method according to the ninth or tenth embodiment is further provided, further comprising the step of converting the nonwoven abrasive article to at least one of a spiral abrasive wheel or an integral abrasive wheel.

  In a thirteenth embodiment, the present disclosure provides a method according to any one of the ninth to twelfth embodiments, wherein the abrasive platelet is a triangular abrasive platelet.

  In a fourteenth embodiment, the present disclosure provides a method according to any one of the ninth to thirteenth embodiments, wherein the abrasive platelets are densely packed along the length of the interlaced fibers.

  In a fifteenth embodiment, the present disclosure provides for the ninth to fourteenth embodiments, wherein the majority of the abrasive platelets are arranged to be orthogonal to the entangled fibers to which the abrasive platelets are bonded. A method according to any one is provided.

  In a sixteenth embodiment, the present disclosure provides a method according to any one of the ninth to fifteenth embodiments, wherein the abrasive platelet is a molded abrasive platelet.

  The objects and advantages of this disclosure are further illustrated by the following non-limiting examples, although the specific materials and their amounts quoted in these examples, as well as other conditions and details, It should not be construed as unduly limiting.

EXAMPLES Unless otherwise indicated, all parts, proportions, ratios, etc. in the examples and the rest of the specification are by weight.

  material

Orientation Test Three 100 × photomicrographs are taken from a representative area of the surface of the web coated with abrasive particles. The micrograph is then examined in detail to determine the qualitative direction of those particles relative to the web fibers. If the particles are adhered to the fiber surface at points or edges, the particles are counted as being oriented radially. When the particles are adhered to the fiber surface of the main surface, the particles are counted as being oriented tangentially. In addition, at the attachment point of each particle, the distance from the center of the fiber to the distal end of the particle is measured.

Abrasive Wheel Abrasive Test A test abrasive wheel 6 inches (15.24 cm) in diameter and 0.5 inches (1.27 cm) thick is attached to the shaft of a stationary Baldor 3 hp motor. Stainless steel pipe workpiece with a diameter of 2.0 inches (5.08 cm) and a thickness of 0.125 inches (3.175 mm) is attached to an SLO-SYN single-phase synchronous motor (SS700) mounted on a movable carriage. It is done. The workpiece is set to rotate around the vertical axis at 32 rpm using an SLO-SYN motor, and the grinding wheel is set to rotate at 3450 rpm using a Bardot motor. The end of the workpiece is pressed against the surrounding grinding wheel with a selectable load of either 8 pounds (3.6 kg) or 10 pounds (4.5 kg) while rotating about its longitudinal axis. During this test, the end of this pre-weighed rotating tube is pressed against the pre-weighed grinding wheel at a selected test load at 15 second intervals, followed by a 15 second non-contact time. It was. Each polishing test is run for a total of 30 minutes, including a total time of 15 minutes for the workpiece to contact the polishing wheel. The total cutting is determined by the weight loss of the workpiece, and the wear of the grinding wheel is determined by the weight loss of the grinding wheel. Results are reported as cutting and wear (grams) for each test abrasive wheel at each test load.

Disc polishing test A non-woven abrasive disc having a diameter of 3 inches (7.62 cm) to be tested is attached to a 3-hp electric servomotor. This motor is arranged on an XY table, and a 1018 carbon steel panel of 6 inches × 14 inches × 1/2 inch (150 mm × 360 mm × 13 mm) is fixed to the XY table. Next, the rotary tool is operated and rotated at 9000 rpm with no load. The abrasive article is then pressed against the panel at a 5 degree angle with a load of 3 pounds (1.4 kg). The tool is then passed through a 12.53 inch (318.3 mm) path at a speed of 4.7 inches / second (120 mm / second) in the -X direction, followed by 14.0 inches / second in the -Y direction. A path of 0.290 inches (7.35 mm) at a speed of seconds (356 mm / second) followed by 12.53 inches (318.3 mm) at a speed of 4.7 inches / second (120 mm / second) in the + X direction. ) Was subsequently set to pass through the 0.290 inch (7.35 mm) route at a speed of 14.00 inches / second (355.6 mm / second) in the -Y direction. This sequence is repeated 10 times and passed 20 times in the X direction. Such 20 passes along the length of the panel are completed in each cycle for a total of 8 cycles. The panel mass is measured before and after each cycle and summed to calculate the cumulative mass loss (cutting) at the end of 8 cycles. The disc is weighed before and after completion of the test (8 cycles) to determine wear. The number of samples tested for each example is reported in Table 3.

Fabrication of Nonwoven Prebond Web A nonwoven web was formed on an airlaid fiber web forming machine available from Land Machine (Macedon, NY) under the trade name “RANDO WEBBER”. The fiber web was formed from 25% 64dtex (58d) nylon 6,6 fiber and 75% 78dtex (70d) nylon 6 fiber. The weight of the web was approximately 415 grams / square meter (gsm) (99 grains / 24 square inches). The nonwoven web was temporarily fixed with a needle to a scrim fabric (16 × 16 plain weave nylon STYLE 6713531, manufactured by Highland Industries, Greensboro, NC). The web was conveyed to a two roll coater where the prebond resin was applied at a dry add-on weight of 586 gsm (140 grains / 24 square inches). The prebond resin had the following composition (all percentages relative to component weight): PU3 54.1%, CUR2 19.9% and PMA 26%. The coated web is passed through a convection oven for 4.5 minutes at 330 ° F. (166 ° C.) to cure the prebond resin to a non-tacky state, having a thickness of about 5.8 mm and a basis weight of 1147 gsm (274 grains). / 24 square inches) of prebonded nonwoven fibrous web was obtained.

Comparative Example A
An adhesive consisting of 51% PR, 46.8% water, 2.1% POL, and 0.1% DYN was sprayed onto the prebond to a wet addition of 210 gsm. Next, SAP1 abrasive particles 402 gsm were applied to the wet coating by drop coating. The particle-coated web was then heated in a convection oven at 88 ° C. (190 ° F.) for 15 minutes, 107 ° C. (225 ° F.) for 15 minutes, and finally at 163 ° C. (325 ° F.) for 15 minutes. The resulting composite was evaluated by a direction test. Three replicates were made. The direction test results are reported in Tables 2 and 3.

Comparative Example B
Comparative Example B was prepared exactly the same as Comparative Example A, except that the adhesive was sprayed to a wet addition of 420 gsm. The direction test results are reported in Tables 2 and 3.

Example 1
Example 1 was prepared exactly as in Comparative Example A, except that the abrasive particles were applied by electrostatic coating. The particles were brought into contact with the plate and then charged to a potential of 11 kV. The particles were electrostatically transferred to the adhesive-coated surface of the web attached to the ground plate against gravity. The particles moved vertically under the force of the electrostatic field, deposited on the individual fibers of the nonwoven web, and were oriented radially. The direction test results are reported in Tables 2 and 3.

Example 2
Example 2 was prepared exactly the same as Example 1, except that 50% of the abrasive particles were applied by drop coating (first time) and then 50% by electrostatic coating. The direction test results are reported in Tables 2 and 3.

Comparative Example C and Examples 3, 4
Comparative example A was sprayed with a size coat consisting of abrasive disc PR 21.4 wt%, PME 13.2 wt%, CA 4.6 wt%, AL 2.5 wt%, BC 0.9 wt%, and MIN 57.4 wt%. A 741 gsm wet addition (177 grains / 24 square inches) was made on Example 1 and Example 2 and then it was cured at 163 ° C. for 15 minutes. This abrasive disc was considered to be Comparative Example C, Example 3 and Example 4, respectively. The resulting composite was evaluated by a disc polishing test. Two replicates were made. The test results are reported in Table 4 below.

  As shown in Tables 2 and 3, when Comparative Example A and Example 1 were compared, the particle orientation by electrostatic coating was greater than that of drop coating. Example 2 shows the amount of orientation between the drip coating and the electrostatic coating by applying half of the particles in each method. Comparative Example B shows how the benefit of orientation rate can be affected by increasing the resin addition level, which causes the particles to fall onto the fiber due to the large amount of coverage. . Table 4 shows the corresponding disc cutting performance for carbon steel. The increase in orientation over Comparative Example C found in Example 3 and Example 4 leads to an increase in disk cutting.

Examples 5 and 6 and comparisons D and F
An integral nonwoven polishing wheel and a spiral nonwoven polishing wheel were produced with and without electrostatic spraying. In the dry spray mineral process, only air is used to advance the abrasive particles onto the web. In the electrostatic process, air is also used to advance the abrasive, but it is also available as EASY SELECT MANUAL POWDER GUN USING A GEMA VOLSTATIC BOX manufactured by Gema USA (Indianapolis, IN). A charge is imparted to the particle through the electrode at the outlet tip of the particle.

Example 5 and Comparative Example D
119 g / m ² of 24 denier nylon fiber air laid nonwoven web, 38.9 parts by weight A1, 35.86 parts by weight water, 21.51 parts by weight WU, and 3.07 parts by weight A2 And spray coating with 30 g / m ² (dry) acrylic / urethane binder consisting of 0.39 parts by weight of Green, 0.26 parts by weight of Black, and 0.0002 parts by weight of DF. 5 integral abrasive wheels were made, followed by heating at 285 degrees Fahrenheit for 6 minutes. Next, 57.8 parts by weight of PU1, 12.14 parts by weight of CUR, 2.89 parts by weight of ER1, 15.03 parts by weight of KBF4, 5.78 parts by weight of PMA, 2. A 174 g / m ² (dry) make coating consisting of 89 parts by weight of LiSt, 2.31 parts by weight of silica and 1.16 parts by weight of PEG was applied by roll coating. Next, 593 g / m ² of SAP2 was applied by electrostatic spraying, followed by heating at 300 ° F. for 5 minutes. Next, 55.59 parts by weight of PU2, 7.73 parts by weight of CUR, 2.78 parts by weight of ER1, 22.79 parts by weight of PMA, 3.34 parts by weight of LiSt, 1. 474 g / m ² (dried) consisting of 95 parts by weight silica, 1.11 parts by weight PEG, 3.34 parts by weight CaSt, 0.56 parts by weight ER2, and 0.83 parts by weight UVA. ) Size resin was applied with a roll coater. The resulting abrasive composition was stacked in eight layers, placed in a mold, and compressed to a thickness of 0.5 inches (1.27 cm). The mold was placed in an oven at 240 degrees Fahrenheit for 6 hours and removed, and the resulting abrasive slab was integrated into an integral 6 inch (15.24 cm) diameter with a final density of 12 g / cubic inch (0.74 g / cm ³ ). Cut into grinding wheels.

  Comparative Example D was prepared in exactly the same way as Example 5 except that SAP2 was applied by air spray instead of electrostatic spray.

Example 6 and Comparative Example E
Example 6 converts the abrasive web composition into a convoluted abrasive wheel by winding 432 inches (11 m) around a 1 inch diameter phenolic core under sufficient tension to yield a final density of 12 g / It was produced in exactly the same way as in Example 5 except that a 6 inch (15.24 cm) diameter grinding wheel with a cubic inch (0.74 g / cm ³ ) was produced.

  Comparative Example E was made exactly the same as Example 6, except that SAP2 was applied by air spray instead of electrostatic spray.

  The performance was measured using the above grinding wheel polishing test. The test results are shown in Table 5. The resulting cut for Comparative Example D was 1.3 times higher for the 8 pound test cut compared to Example 5 and 1.7 times higher for the 10 pound test cut. The results of Example 6 were 1.6 times higher for the 8 pound test cut and 1.2 times higher for the 10 pound test cut compared to Comparative Example E. Each photo shows the SAP2 tip of an integral structure oriented to a stainless steel workpiece when applied using a dry mineral spray device and the workpiece when applied by an electrostatic process. The tip of SAP2 of the oriented spiral structure is shown.

  All references, patent documents or patent applications cited in the above applications for patent certificates are hereby incorporated by reference in their entirety in a consistent manner. In case of discrepancies or inconsistencies between the incorporated reference parts and the present application part, the information in the above description will prevail. The foregoing description, which is presented to enable any person skilled in the art to practice the claimed disclosure, is to be construed as limiting the scope of the disclosure as defined by the claims and all equivalents thereof. Should not.

Claims (14)

A bulky and coarse nonwoven fibrous web containing entangled fibers;
An abrasive platelet fixed to the entangled fibers by at least one binder material,
The majority of the abrasive platelets are each bonded to at least one of the entangled fibers in the edge direction;
A nonwoven fabric abrasive article in which the majority of the abrasive platelets are disposed such that the principal surfaces of the abrasive platelets are orthogonal to the entangled fibers to which they are bonded.   The nonwoven fabric abrasive article according to claim 1, wherein the abrasive platelet comprises a triangular abrasive platelet.   The nonwoven fabric abrasive article according to claim 1 or 2, wherein the abrasive platelets are densely packed along the length of the entangled fibers.   The nonwoven fabric abrasive article according to any one of claims 1 to 3, wherein the nonwoven abrasive article comprises a hand pad; a floor pad; or a surface finish pad, a disk, or a belt.   The nonwoven fabric abrasive article according to any one of claims 1 to 4, wherein the abrasive platelets have nominally the same size and shape.   6. The abrasive platelet as claimed in any one of the preceding claims, wherein the abrasive platelet comprises a shaped abrasive platelet that is bounded by upper and lower surfaces and a plurality of sidewalls disposed therebetween. Nonwoven abrasive article.   A spiral nonwoven fabric polishing wheel comprising the nonwoven fabric abrasive article according to any one of claims 1 to 6 wound and compressed spirally. A method for producing a nonwoven abrasive article comprising:
i) providing a bulky and coarse nonwoven fibrous web comprising a plurality of entangled fibers;
ii) coating at least a portion of the bulky, unwoven nonwoven fibrous web with a first curable binder precursor to provide a coated fibrous web ;
i ii) electrostatically depositing a plurality of abrasive platelets on at least a portion of the first curable binder precursor;
iv) at least partially curing the first curable binder precursor;
Including
The majority of the abrasive platelets are each bonded to at least one of the entangled fibers in the edge direction;
The method, wherein the majority of the abrasive platelets are arranged such that the major surfaces of the abrasive platelets are orthogonal to the entangled fibers to which they are bonded.   Coating at least a portion of the first curable binder precursor and abrasive platelet with a second curable binder precursor; and at least partially curing the second curable binder precursor; The method of claim 8, further comprising:   10. The method further comprises converting the nonwoven abrasive article into at least one of at least one hand pad; at least one floor pad; or at least one surface finish pad, disk, or belt. The method described in 1.   10. The method of claim 8 or 9, further comprising the step of v) converting the nonwoven abrasive article to at least one of a spiral abrasive wheel or an integral abrasive wheel.   The method of any one of claims 8 to 11, wherein the abrasive platelet comprises a triangular abrasive platelet.   13. A method according to any one of claims 8 to 12, wherein the abrasive platelets are dense along the length of the entangled fibers.   14. The method of any one of claims 8 to 13, wherein the abrasive platelet comprises a molded abrasive platelet.